"Veteran" conjures up images of old, worn-out folks, well past their prime in their lifetime endeavor(s). I'm not really sure that I want to reach "veteran" status! I would prefer "experienced" or "accomplished". Most chasers who have spent 10-15 years on the Plains chasing for a couple of weeks (at least) each spring have reached this level, in my humble opinion.
It took me a good 4 to 5 years of chasing before I felt like I had a clue. It took me about 10-12 years before I felt relatively comfortable with my forecasting skills, and satisfactorily familiar with severe storm morphology and development. Nowadays, it is easier to be on better storms earlier and longer, so the road to "veteran chaser" status is faster than 15-30 years ago. Also, I don't think that the number of tornadoes seen or not seen should be part of the equation...though I suppose you could categorize the "experienced chasers" into smart veterans, dumb veterans, lucky veterans, eternally-jinxed veterans, etc.
Having said that, just for fun, here are some criteria which likely apply to veteran chasers:
They chased prior to Mr. Roboto.
They chased when Doswell had hair.
Their first camcorder used real film, and their first highlights video had no audio.
They knew where the NWS offices in Scottsbluff, Grand Island, and Colorado Springs were.
They had to deal with 55-mph speed limits, even in the middle of nowhere, for years and years, thanks to Jimmy Carter.
They had one of their radio push-buttons set to 530 AM.
They chased before the F-scale had been invented, and before Bill and Jo visited Wakita.
After they saw a tornado, there was no one else around to discuss it with...and they had to wait a week or two to see if the images that they captured came out or not.
They chased when rooms at Super 8 were 8 bucks, and when all they wanted at a motel was a room with cable TV and TWC, a phone jack, and a three-pronged electrical outlet.
They knew their NGMs from their LFMs.
Finally, a veteran chaser is one who chased when stormchasing wasn't cool.
Bill Reid